Indicator



E. E. MARLIN Oct. 25, 1932.

INDICATOR filed Dec. 20, 1926 ATTORNEY Patented Oct. 25, 1932 EL'MER E.MARLIN, OF DETROIT, MICHIGAN rumoa'ron Application filed December 20,1926. Serial No. 156,050.

This invention relates to an indicator and more particularly to anindicator for determining a free passage through a conduit.

In the manufacture of concealed passages such as in radiators, pipelines or manifolds for internal combustion engines, any obstructiontherein has been difficult to detect until the passage is in use. Theseobstructions are more often found in castings, varying insize,

"" often large enough to entirely obstruct the passage. If theobstruction is not discovered before the device is put into operationconsiderable di'fliculty may result.

It is therefore an important object of this invention to provide a meansfor determining whether or not there is a free passage through theconduit, illustrated by a device for forcing a current of air throughthe passage and 1ndicating any back pressure on that current of 1:0 all.

Another object of the invention is to provide an adjustment for thedevice whereby the pressure, at the point of the back pressure ndicator,may be varied depending on the slze of the concealed passage.

A further object is to provide means for indicating the size of theobstruction which has been shown as a graduated opening adapted torelieve the back pressure caused by the 311:: obstruction.

These and other objects of the invention will more fully appear from thefollowing description taken in connection with the accompanying drawing,in which:

Fig. 1 is a side elevation of the device, parts being in section,applied to a hot air passage around an intake manifold.

Fig. 2 is a sectional view through the de- .vice for indicating the sizeof an obstruction,

4o taken on line 2-2 of Fig. 1.

Fig. 3 is a sectional view on l1ne 33 of Fig. 1 showing the method ofsecuring and sealing the device in a passage to be tested.

Referring to the illustrated embodiment of my invention, an intakemanifold 10, for use on an internal combustion engine, has been 4 shownhaving a passage 12 surounding the manifold constituting a bypass froman exhaust manifold 14. The exhaust gases enter the manifold 14 throughopenings 16 and are exhausted through an opening 18. A portion of theexhaust gases, however, pass through an opening 20 into the passage 12around the manifold, returning to the exhaust manifold through opening22and passage 24.

The purpose of-the passage around the intake manifold is to heat thelatter to cause better vaporization of the fuel and when this passage isrestricted its efliciency is reduced.

The device for testing the flow of air through the passage has beenillustrated as comprising a conduit adapted for communication with thepassage, means for supplying a predetermined air pressure therethru andmeans for indicating any resistance or back pressure on that airpressure. Referring more specifically to the illustrated device, aconduit 26 has one end provided with a connection 28 having a passage30. The lower end of the connection is provided with a cylindricalportion 32 adapted to fit an opening 34 in the manifold, the lower endof said cylindrical portion being closed. An opening 36 is formed on theside of the cylindrical portion 32, adapted to register with 75 thepassage 24 and communicate with the passage 30. A collar 38 and gasket40 position the cylindrical portion in the-opening 34. The upper end ofthe connection 28 is provided with a cap 42 which receives a screwthreaded rod 44 having a handle 46 at one end thereof and a tapered endportion 48 at, the other end. Slidably mounted in the wall of thecylindrical portion 32 is a member 50 having a tapered opening 52slightly larger than the tapered end portion 48 .of the rod 44. When theopening 86 isaligned with the passage 24 the rod 44 is screwed down withthe tapered end 48 engaging one side of the tapered opening 52, forcingthe member 50 firmly against the side of the opening 34, thus securingthe device in position. To insure a proper seal, packing 54 has beenprovided between the cylindricalportion 32 and periphery of the openingto the passage The conduit 26 isprovided with a passage 56 and has anadjustable tube 58 screwthreaded therein which is connected to an airpressure supply regulated by a suitable valve 60. we

Adjacent the inner end of the adjustable tube 58 and located in theconduit 26 at an acute angle to the direction of air fio-w, is a fitting62 having a passage 64 Communicating with the passage 56 and open toatmospheric pressure; Within the passage 64- is a one way valve, shownas a ball 66 fitting a seat 68.

When a pressure is applied througl i the tube 58, passages 56 and 30,opening 36 and passages 24, 22, 12 and 20, the ball 66 rests on its seat68 when there is: a free passage of air through the said passages but inthe event of an obstruction a back pressure is formed and the ball 66 isforced away from its seat visible through a slot 70 in the fitting 62.Thus when the passage to be tested is free, there is nomovement of theball andwhen it is obstructed the ball 66 flutters indicating theobstruction. I

The back' pressure or effective pressure on the ball 66, may be variedby thelocation of the end of-the tube 58. The smaller area, whencommunicating with the larger area, acts as a ven-turi and bypositioningthe end ofthe tube with respect to the passage64, varyingpressures may be obtained adjustable to the size of a given passage tobe tested. A look nut 72 retains the tube in adjusted position.

As shown in Fig. 2, a means has been provided for determining the sizeof the ob-. struction. An adjustable valve 75, shown asa screw threadedtapered. member 74, adapted to engage a corresponding tapered seat,forms a relief for the back pressure caused by the obstruction. Whenthis valve has been opened sufiiciently to overcome the back pressure,the ball 66, or indicator stops fluttering and the relation of theopening through the valve is proportionate to the of the obstruction,Thus by graduating the valve, illustrated by a graduated member 7 6adjacent an indicator 7 8 forming the handle of the valve, a reading maybe taken thereby determining the size of the obstruction.

While I have described what I deem to be the preferred embodiment of myinvention it is to be understood that various changes may be madewithout. departing from the spirit thereof and it is not my intentiont-olimit' its scope other than by the terms of the appended claims.

What I claim is: [I

1. Ina device of the class described comprising, a conduit adapted forcommunication with an open passage, means for supplying a current of airthrough said conduit and passage, means for indicating aback pressurecaused restricting theflow of said air current, and means for varyingthe amount of pressure adjacent said indicating means.

2. In a'device of the class described comprising, a conduit adapted forcommunicating Withfi passage, means for supplying a current of airthrough said conduit and passage, means for indicating a back caused byrestricting the flow of said air pressure current, and graduated meansfor relieving formed through said conduit and passage, an

axially adjustable conduit within said first mentioned conduit, meansforconducting a current of air through said conduits and passage, andmeans for indicating any back pressure caused by-restricting said aircurrent.

In a device of the class described comprising, a conduit having one endprovided with an opening and means for securing it to a member providedwith a passage whereby a continuous passage is formed through saidconduit and passage, an axially acliustablc conduit within said firstmentioned couduit, means for conducting a current of air through saidconduits and passage, means for indicating any back pressure caused byrestricting said air current, and graduated means for relieving saidback pressure.

5. In a device of the class describedcomprising, a conduit, means forsecuring said conduit in communication with an open passage, meansforsupplying a current of air through saidconduit and passage, a passagefor the escape of air from said conduit communicating with the aircurrent in said condnit.v and a member in said passage movable by anyback pres we in the current of air.

6. In a connccwon of the class described comprising a tubular memberhaving a closed end portion and an opening in its wall adapted to bereceived in an opening formed in a member provided with a passage, aslidable member projecting through the wall of said tubular memberopposite said first named opening, packing around the periphery of said013811111 nd nice. 2; for forcing said slid c7 5 able member outwardlyagainst the wall of tubular member said member to retain said position.

7. In a device of the class described com prising, a conduit, means forsecuring said conduit in communication with a passage. a conduit screw?threaded within said first named conduit, a valve for regulating acurrent of air through said conduits and pas sage, a fitting providedwith an. opening communica-ting with said air current and open toatmospheric pressure, a member in said fitting adapted to close saidopening and adapted formovement by a pressure greater than atmosphericpressures within said conduits, and a graduated valve for relieving thepressure causing movement of said member. V

ELMER MARLIN.

